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| Main Authors: | , , , , |
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| Format: | Preprint |
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2026
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| Online Access: | https://arxiv.org/abs/2603.02693 |
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| _version_ | 1866917308892446720 |
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| author | Guo, Ruiping Chen, Haowei Duan, Wenhui Xu, Yong Wang, Chong |
| author_facet | Guo, Ruiping Chen, Haowei Duan, Wenhui Xu, Yong Wang, Chong |
| contents | In ordinary solids, nonlinear optical responses are typically studied in terms of unit-cell averages due to the angström-scale lattice constants. In contrast, moiré superlattices, characterized by a large length scale, unlock an often-overlooked degree of freedom: intra-supercell spatial variations of local observables. Here, we formulate the second-order direct current (DC) charge response in a spatially resolved manner, showing that even uniform optical illumination can drive a static, spatially non-uniform charge redistribution within a supercell. This effect is ubiquitous and cannot be forbidden by any crystalline symmetries. Furthermore, we identify a dominant contribution arising from diverging analytical response coefficients, which leads to linear-in-time growth of the redistribution in the absence of relaxation. This growth is driven by the convergence or divergence of local DC photocurrents. Applying our theory to twisted bilayer MoTe$_2$, we demonstrate strong, highly tunable charge modulation controlled by light intensity and frequency, opening a route to in situ, all-optical control of moiré-periodic electrostatic potentials. Our work underscores the importance of intra-cell degrees of freedom, which enable a qualitatively richer class of nonlinear optical responses in moiré superlattices. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2603_02693 |
| institution | arXiv |
| publishDate | 2026 |
| record_format | arxiv |
| spellingShingle | Manipulating Charge Distribution in Moiré Superlattices by Light Guo, Ruiping Chen, Haowei Duan, Wenhui Xu, Yong Wang, Chong Materials Science In ordinary solids, nonlinear optical responses are typically studied in terms of unit-cell averages due to the angström-scale lattice constants. In contrast, moiré superlattices, characterized by a large length scale, unlock an often-overlooked degree of freedom: intra-supercell spatial variations of local observables. Here, we formulate the second-order direct current (DC) charge response in a spatially resolved manner, showing that even uniform optical illumination can drive a static, spatially non-uniform charge redistribution within a supercell. This effect is ubiquitous and cannot be forbidden by any crystalline symmetries. Furthermore, we identify a dominant contribution arising from diverging analytical response coefficients, which leads to linear-in-time growth of the redistribution in the absence of relaxation. This growth is driven by the convergence or divergence of local DC photocurrents. Applying our theory to twisted bilayer MoTe$_2$, we demonstrate strong, highly tunable charge modulation controlled by light intensity and frequency, opening a route to in situ, all-optical control of moiré-periodic electrostatic potentials. Our work underscores the importance of intra-cell degrees of freedom, which enable a qualitatively richer class of nonlinear optical responses in moiré superlattices. |
| title | Manipulating Charge Distribution in Moiré Superlattices by Light |
| topic | Materials Science |
| url | https://arxiv.org/abs/2603.02693 |